Relation between total renal volume and renal function: Usefulness of 3D sonographic measurements with a matrix array...

The aims of this study were to evaluate the reproducibility of 3D sonography with a matrix array transducer as a means of measuring renal volume and to investigate correlations between renal volume and renal function.

One hundred twenty subjects (20 consecutively registered patients with one of the five stages of chronic renal disease and 20 healthy volunteers [stage 0 renal function]) were enrolled. Individual renal volume was determined by two independent observers using 2D sonographic and 3D matrix array transducer sonographic data. The reproducibility of volume measurement was evaluated for both of these methods. After total renal volume was normalized to body surface area, correlations between normalized total renal volume and estimated glomerular filtration rate (GFR) were evaluated. Differences in normalized total renal volume related to stage of renal function also were evaluated.

The reproducibility of 3D sonographic measurements obtained with a matrix array transducer was greater than that of 2D sonographic measurements. The correlation between normalized total renal volume obtained with matrix array transducer 3D sonography and estimated GFR for two observers (r = 0.809 and 0.813; p < 0.001) was better than that between normalized total renal volume obtained with 2D sonography and estimated GFR (r = 0.696 and 0.715; p < 0.001). The mean normalized total renal volumes obtained with matrix array transducer 3D sonography in stages 0 and 1 were significantly larger than those in other stages (p < 0.001). The mean normalized total renal volume in stage 5 disease was significantly smaller than the volumes in the other stages (p < 0.001).

Three-dimensional sonography with a matrix array transducer is a reliable means of measuring renal volume during evaluations of patients with reduced renal function.